Over the past decade or so, astronomers have speculated about the characteristics of rogue planets in the Milky Way galaxy. These "free-floating" worlds don't orbit stars, but instead roam the ...

IMAGE: An artist’s impression of a free-floating planet. Using observations and archival data from several of NSF’s NOIRLab’s observatories, together with observations from telescopes around the world ...

Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system was touted more than a century ago. But ...

The Gaia telescope spotted more than 6,000 sunlike stars, all of which appear to have migrated from the galaxy's center more ...

LOS ANGELES - The Milky Way is home to at least 17 billion planets that are similar in size to Earth, a new estimate suggests. That's more than two Earth-size planets for every person on the globe.

Planetary systems in the Milky Way galaxy tend to follow a particular pattern: rocky planets toward the center, closest to the host star, and gas planets toward the exterior. That’s how planets are ...

PRINCETON, N.J. (CNN/CNN Newsource/WKRC) — A new planet was possibly discovered beyond the planet Neptune. Researchers from the Institute for Advanced Study's School of Natural Sciences have announced ...